In automatic pinspotter bowling machines a member on each side of the machine acts to guide the bowling pins to the pin pickup mechanism at the rear of the machine. These members, known as "plows" because of their resemblence to agricultural plows, are made of metal. The plows are continuously battered by bowling pins that have been hit by the bowling balls. Eventually, the plows suffer metal fatigue and crack from the battering by the pins. They then have to be removed and repaired by welding, or replaced. Failure to remove a cracked plow will result in the bowling pins themselves being cut by the exposed edges along the crack. Welding the cracked plow is itself often unsatisfactory: if the weld is higher than the adjacent surface of the plow, the weld itself will cut the pins.